Particulate material storage bins are commonly used on farms for storing the grain. In some instances the grain bins include a flat bottom from which the cylindrical wall of the bin extends upwardly. In this instance an additional mechanism to assist in unloading the auger is desirable as disclosed in U.S. Pat. Nos. 6,349,859 and 6,237,813 both by Epp et al.
In other instances it is desirable for the grain bin to comprise a hopper bottom which is generally conical so as to taper downwardly and inwardly to the center to assist in center unloading of the grain bin. Such hopper bottoms may be formed integrally with the grain bin or may be for as a separate component upon which a commercially available cylindrical bin is then supported. Canadian patent application 2,008,299 by Weninger discloses an example of a grain bin hopper bottom in which the tapering cone portion terminates at a central bottom end spaced above the ground to receive an auger inlet therebelow. In this instance the grain commonly spills onto the ground about the auger requiring considerable effort to clean up. In some instances a separate boot is mounted about the inlet end of the auger in the form of a collection hopper which directs material exiting the cone of the grain bin hopper bottom to the inlet of the auger. Use of a separate hopper boot attached to the auger can be cumbersome and awkward to manipulate.
Another known hopper bottom, previously made commercially available by Westeel under the trademark name the “Boot”, comprises a conical hopper portion which is surrounded by a cylindrical outer wall which supports the cone and the cylindrical bin walls thereabove. The bottom end of the cone portion includes an integral upper boot structure suspended above the floor of the hopper bottom with minimal access provided only by an auger opening spaced above the floor so that the boot is difficult to clean out. Ventilation of the grain in this hopper bottom is made available by a plurality of perforated channels protruding into the cone portion of the hopper bottom. Similar to many prior designs however the perforated channels project upwardly and inwardly beyond the inner surface of the cone portion of the hopper bottom so as to impede grain flow along the surface of the hopper towards the central discharge through the boot. Accordingly the grain bin is very difficult to clean out as considerable grain can be trapped on the various protruding surfaces of the ventilation system. Furthermore the cup shaped enclosed lowest point of the boot further prevents adequate cleanout of the grain bin when desired.
Further examples of grain drying through a hopper cone are disclosed in
U.S. Pat. No. 5,604,994 by Annen et al. and U.S. Pat. No. 4,520,714 by Gullickson. In each instance a portion of the ventilation system protrudes inwardly into the interior of the hopper cone so as to impede the flow of material downwardly to the central discharge thereof, thus preventing adequate cleanout after the bin has been emptied.